The present invention relates to a height adjustment mechanism for a vehicle seat shoulder belt and in particular to a height adjustment for a shoulder belt of a child's seat.
Special child seats that provide protection for infants and small children in motor vehicles are well known. Two different types of child seats have been developed. One type is a separate seat which is placed upon a vehicle seat and attached thereto by the seat belt provided as part of the vehicle seat. A second type of child seat is commonly referred to as an "integral child seat" in which the components of the child seat are built into the vehicle seat. Integral child seats typically include one or more moveable components which, in one position, enable use of the seat by an adult, and in a second position enable use of the seat by a small child. Common elements of both types of child seats are a generally horizontal seat support, a back panel and a restraint system for the seat occupant. Restraint systems generally include a shoulder belt which is operatively connected between the back panel and the seat support to restrain a passenger positioned on the seat support and against the back panel.
In order to accommodate children as they grow in size, adjustment of the shoulder belt height on the back panel is required. With the separate, add-on child seats, shoulder belt height adjustment is made simple by virtue of the fact that the seat is removable, providing easy access to the rear of the back panel. The back panel is made with two or more vertically spaced apart slots for each shoulder belt, and the belt system is constructed such that the belts can be removed from one slot and rethreaded through another slot to make the necessary height adjustment.
However, with the integral child seats, access is typically not available to the rear of the back panel, precluding disassembly of the restraint system for adjusting the shoulder belt height. A common approach to provide adjustment is to connect the spaced apart shoulder belt restraint slots with a connecting passage in the back panel. The connecting passage allows the shoulder belts to be moved from one slot, through the connecting passage, to another slot without withdrawing the shoulder belt from the back panel. An example of such an adjustment mechanism is shown in FIG. 1. A child seat back panel 100 is shown having left and right sets 102 of shoulder belt restraint slots 104, 106, 108. Shoulder belts 110 are shown passing through the back panel in lower restraint slots 108. The restraint slots are connected to one another at the outboard ends of the restraint slots by horizontal adjustment slits 112, 114, 116 which are coupled to vertical connector slits 118.
The vertical connector slits extend downward beyond the lowest restraint slot 108 of each set forming extensions 120. The extensions enable the shoulder belts to be moved from one restraint slot to another without twisting the shoulder belts. This is accomplished, for example, by moving a belt 110 from the lowest restraint slot 108, through its transfer slit 116 and moving the belt outboard edge 122 down into the extension 120. This is followed by moving the belt upward and into the intermediate restraint slot with the inboard edge 124 of the belt leading into the intermediate restraint slot 106. This avoids a twist in the shoulder belt which, if present, can interfere with the proper functioning of the child seat restraint system.
In the example shown in FIG. 1 with three restraint slots, it is possible to properly adjust the should belt height without twisting the shoulder belt and without the need for the downward extension 10 of the connector slit. However, in a system having only two restraint slots, a separate extension of the connector slit is required to make an adjustment without twisting the shoulder belt.
While the adjustment mechanism shown in FIG. 1 enables the shoulder belt height to be adjusted without twisting the shoulder belt, it does not preclude the possibility of an incorrect adjustment in which the extension 120 of the connector slit 118 is not used and the shoulder belt is adjusted by inserting the shoulder belt into a restraint slot with the belt's outboard edge leading, thereby placing a twist in the shoulder belt.
Accordingly, it is the object of the present invention to provide a shoulder belt height adjustment mechanism which precludes incorrect adjustment and in which the shoulder belt can only be adjusted in a manner that does not twist the shoulder belt.
The shoulder belt height adjustment mechanism of the present invention provides a transfer passage between the restraint slots which connects to opposite ends of the restraint slots. For example, the transfer passage will connect the inboard end of one restraint slot with the outboard end of the next vertically adjacent restraint slot. As a result, when the shoulder belt is adjusted, the edge of the shoulder belt, which leads as the belt leaves the first slot, also leads as the belt enters the next slot. However, since it is entering the second slot at the opposite end from which the belt exited the first slot, no twisting results in the shoulder belt. Furthermore, the transfer passage does not permit an incorrect adjustment to be made by twisting the belt. The concept of the invention can be utilized with any number of vertical spaced restraint slots.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.